Integrated U-tube and adsorbent unit

ABSTRACT

An integrated U-tube and adsorbent unit including a U-tube having first and second legs and a return bend, a space between the first and second legs and the return bend, adsorbent in the space, opposite sides on the first and second legs and the return bend, permeable covers bonded to the first and second opposite sides to contain the adsorbent within the space, a hole in the return bend, a frame connected to the U-bend and defining a space in communication with the hole, and filter material on the frame. An integrated U-tube and adsorbent unit including a plastic U-tube and a self-contained adsorbent unit having a plastic cover bonded to the U-tube with the body of the self-contained adsorbent unit positioned between the legs of the U-tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a continuation-in-part of applicationSer. No. 09/603,415, filed Jun. 26, 2000.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not Applicable

BACKGROUND OF THE INVENTION

[0003] The present invention relates to an integrated U-tube andadsorbent unit for an accumulator of an automotive air conditioningsystem.

[0004] By way of background, insofar as known, in the past a refrigerantaccumulator used in an automotive air conditioning system comprised ahousing which contained a U-tube and a separate adsorbent unitassociated therewith. The adsorbent unit, in the past, could have beenof various shapes and sizes and could have been secured to the U-tube inmany different ways. However, insofar as known, the prior art did notdisclose an integrated U-tube and adsorbent unit wherein the adsorbentunit was an integral part of the U-tube. Also, insofar as known, in thepast a separate filter construction was mounted on the return bend of aU-tube to filter the oil which was induced into the return bend. Theaddition of such a filter construction added costs which resulted fromthe additional material and labor. Also, insofar as known, in the pastrefrigerant tracer dye was generally placed directly in the adsorbentunit of an accumulator of an automotive air conditioning system.

BRIEF SUMMARY OF THE INVENTION

[0005] It is the primary object of the present invention to provide anintegrated U-tube and adsorbent unit wherein the adsorbent unit is anintegral and inseparable part of the U-tube.

[0006] Another object of the present invention is to provide anintegrated U-tube and adsorbent unit which can be fabricated by a simplefabrication technique wherein the space between the legs of the U-tubecontains adsorbent which is restricted therein by covers bonded to theouter sides of the U-tube.

[0007] Another object of the present invention is to provide anintegrated U-tube and adsorbent unit which does not require the assemblyof a separate U-tube and adsorbent unit after they are individuallyfabricated incidental to installing them in the housing of anaccumulator.

[0008] A further object is to provide an improved method of fabricatinga U-tube having an integral adsorbent unit.

[0009] A still further object of the present invention is to provide animproved U-tube having an unique filter construction.

[0010] Yet another object of the present invention is to provide animproved U-tube construction which includes a separate compartment whichcontains refrigerant tracer dye. Other objects and attendant advantagesof the present invention will readily be perceived hereafter.

[0011] The present invention relates to an integrated U-tube andadsorbent unit comprising a U-tube having first and second legs and areturn bend, a space between said first and second legs, adsorbent insaid space, and at least one permeable cover bonded to said legs.

[0012] The present invention also relates to an integrated U-tube andadsorbent unit comprising a plastic U-tube having first and secondplastic legs and a plastic return bend, a plastic cover, adsorbentconfined by said plastic cover, and said plastic cover being fused tosaid plastic U-tube.

[0013] The present invention also relates to a method of fabricating anintegrated U-tube and adsorbent unit comprising the steps of providing aU-tube having legs and a return bend with a space between said legs andfirst and second opposite sides on said legs, providing a first cover onsaid first sides of said legs, placing adsorbent between said legs, andbonding a second cover to said second sides of said legs.

[0014] The present invention also relates to a U-tube comprising spacedlegs and a return bend, an oil pick-up hole in said return bend, a frameformed integrally with said return bend to define a space incommunication with said hole, and filter material bonded to said frameon the opposite side of said space from said hole.

[0015] The present invention also relates to a refrigerant tracer dyeconstruction comprising a tube, and a refrigerant tracer dye compartmenton said tube.

[0016] The various aspects of the present invention will be more fullyunderstood when the following portions of the specification are read inconjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0017]FIG. 1 is a cross sectional view taken substantially along line1-1 of FIG. 2 with portions broken away and showing the improvedintegrated U-tube and adsorbent unit mounted in an accumulator of anautomotive air conditioning system;

[0018]FIG. 1A is a cross sectional view taken substantially along line1A-1A of FIG. 1 with the accumulator housing omitted;

[0019]FIG. 2 is a plan view of the integrated U-tube and adsorbent unittaken substantially in the direction of arrows 2-2 of FIG. 1;

[0020]FIG. 3 is a cross sectional view taken substantially along line3-3 of FIG. 1;

[0021]FIG. 4 is an enlarged fragmentary detail view showing thepermeable cover bonded to a ridge on the U-tube and taken substantiallyalong line 4-4 of FIG. 1 with certain parts omitted;

[0022]FIG. 5 is a view similar to FIG. 4 but showing a different type ofbonded connection between the permeable cover and the ridge on theU-tube;

[0023]FIG. 6 is a side elevational view of the U-tube of FIGS. 1-4 andshowing the ridge on the legs and return bend of the U-tube;

[0024]FIG. 6A is a fragmentary cross sectional view taken substantiallyalong line 6A-6A of FIG. 6 and showing an alternate arrangement of holeplacement in the return bend;

[0025]FIG. 7 is an enlarged cross sectional view taken substantiallyalong line 7-7 of FIG. 6;

[0026]FIG. 8 is a side elevational view of the U-tube of FIG. 6 takensubstantially in the direction of arrows 8-8 of FIG. 6;

[0027]FIG. 9 is a side elevational view of another U-bend constructionwhich can be integrated with an adsorbent unit;

[0028]FIG. 10 is a cross sectional view taken substantially along line10-10 of FIG. 9 and showing the halves of the U-tube separated;

[0029]FIG. 11 is a view taken substantially in the direction of arrows11-11 of FIG. 9 and showing the halves of the U-tube separated;

[0030]FIG. 12 is a schematic view showing the first step of the methodof fabricating an integrated U-tube and adsorbent unit by bonding acover to one side of the U-tube;

[0031]FIG. 13 is a schematic view showing a subsequent step infabricating an integrated U-tube and adsorbent unit by filling the spacebetween the U-tube's legs with adsorbent;

[0032]FIG. 14 is a schematic view showing the last step of fabricatingan integrated U-tube and adsorbent unit by bonding a cover to the openside of the U-tube to confine the adsorbent between the legs of theU-tube;

[0033]FIG. 15 is a fragmentary side elevational view of a return bend ofa U-tube which mounts a separate compartment for a refrigerant tracerdye;

[0034]FIG. 16 is a fragmentary cross sectional view taken substantiallyalong line 16-16 of FIG. 15;

[0035]FIG. 17 is a side elevational view of an adsorbent unit which canbe integrated onto a U-bend;

[0036]FIG. 18 is an end elevational view taken substantially in thedirection of arrows 18-18 of FIG. 17;

[0037]FIG. 19 is a side elevational view of a U-tube onto which theadsorbent unit of FIGS. 17 and 18 can be integrated;

[0038]FIG. 20 is a cross sectional view taken substantially along line20-20 of FIG. 19;

[0039]FIG. 21 is a side elevational view, partially broken away, showingthe adsorbent unit of FIGS. 17 and 18 integrated onto the U-tube ofFIGS. 19 and 20;

[0040]FIG. 22 is a cross sectional view taken substantially along line22-22 of FIG. 21; and

[0041]FIG. 23 is a cross sectional view taken substantially along line23-23 of FIG. 21.

DETAILED DESCRIPTION OF THE INVENTION

[0042] The integrated U-tube and adsorbent unit 10 of the presentinvention is shown mounted in an accumulator housing 11 which includes asubstantially cylindrical bottom portion 12 which has welded thereto anupper portion 13 along annular weld 14. Upper portion 13 has integrallyformed therewith an inlet tube 15 which conducts a mixture ofrefrigerant liquid and gas from an evaporator to the inside of theaccumulator, with the liquid dropping to the bottom and the gaseousrefrigerant rising to the top. The gaseous refrigerant will be inducedinto the open end 17 of U-tube 19 and will pass through leg 20, U-bend21 and leg 22 to outlet conduit 23 which leads to the compressor. Anoil-inlet hole or orifice 26 (FIG. 6) is located at the underside ofU-bend 21 to entrain oil located at the bottom of the accumulatorhousing, and this oil is conveyed along with the gaseous refrigerant tothe compressor. The foregoing type of operation is well known in theart. The basic U-tube 19 exclusive of the frame 41 on the return bend21, exclusive of the housing for the refrigerant tracer dye andexclusive of the structure for mounting the covers on the sides of theU-tube is a prior art construction which has ears 18 which bear againstthe inside of container bottom portion 12.

[0043] The integrated U-tube and adsorbent unit 10 of the presentinvention includes the above described U-tube 19 having legs 20 and 22connected by U-bend 21. It is fabricated of blow-molded polyethylene byconventional blow-molding fabrication techniques. It includes twoopposite sides 24 and 24′ which are essentially mirror imagecounterparts about centerline 25 (FIG. 7). On one side of U-bend 19, acontinuous ridge 27 is molded integrally with legs 20 and 22 and U-bend21, as shown in FIG. 6. More specifically, the continuous ridge 27includes sections 29 and 30 on legs 20 and 22, respectively, aconnecting portion 31, which connects portions 29 and 30 and is locatedon U-bend 21, and a connecting portion 32 which connects the upperportions of ridge portions 29 and 30. A ridge 27′ (FIGS. 7 and 8), whichis the mirror image of ridge 27, is located on the other side 24′ of theU-tube. An hour glass shaped section 33 (FIG. 7) is added to the basicU-tube 19 to provide a closure which closes the gap between the upperportions 34 and 35 of legs 20 and 22, respectively, and the upper curvedportions 32 and 32′ of ridges 27 and 27′.

[0044] There is a space 37 (FIG. 6) between U-tube return bend 21, legs20 and 22, and hour glass member 33. This space is filled with adsorbent39 (FIG. 1) which is preferably molecular sieve, but may be of any othersuitable type such as silica gel. Permeable covers 40 and 40′ (FIGS. 1and 3), which are preferably web-bonded polyester felt and which are ofthe same shape as ridges 27 and 27′, respectively, are preferablyheat-fused along their outer edges to ridges 27 and 27′, respectively,or they may be bonded to ridges 27 and 27′ by ultrasonic welding orvibration welding any other suitable bonding means which may include,without limitation, any other type of fusion or the use of bondingcement or any other suitable means of attachment. Permeable covers 40and 40′ may be fabricated out of any other suitable material. While itis preferable to have both covers permeable, it will be appreciated thatonly one permeable cover may be used. The other cover may be impermeablematerial which is bonded to the side of the U-tube or it may be a platewhich is molded integrally with or otherwise attached to the U-tube.

[0045] In FIG. 5, an alternate bonding connection is shown for securingthe edge of the cover to the ridge. In this respect, cover 140, which isanalogous to cover 40, rests on the surface 60 of ridge 127, which isanalogous to ridge 27. A tab 61 which projects from the edge of ridge127 is rolled over onto the edge of cover 140, and thereafter bonding iseffected by any suitable method, such as vibration welding, sonicwelding, heat and pressure welding, or any other suitable type ofwelding or attachment.

[0046] The space within the legs 20 and 22 may effectively be enlargedto contain a desired amount of adsorbent by increasing the height of oneor both ridges 27 and 27′. Also, if the space within the legs 20 and 22and return bend 21 is too large for the desired amount of adsorbent, apartition 36, which is shown in phantom lines in FIG. 6, can beinstalled between the inner sides of legs 20 and 22 in sealingrelationship therewith, and the space for adsorbent would be defined bythe legs 20 and 22, the partition and the return bend 21, or the spacewould be defined by the legs 20 and 22 and the partition and the hourglass section 33. It will be appreciated that the outer edges ofpartition 36 will lie in the same planes as the outer surfaces of ridges27 and 27′ to which the covers are bonded. The partition would be placedat any desired area, as determined by the volume required for theadsorbent. Preferably, the adsorbent is placed in the space immediatelyabove the U-bend. It will be appreciated that if the adsorbent is placedin the space above or below the partition, the permeable cover need onlybe bonded to the portions of the ridge 27 or 27′ and the partition 36which surround the space in which the adsorbent is contained.

[0047] As noted above, the underside of U-bend 21 includes anoil-receiving hole 26 (FIG. 6). In accordance with another aspect of thepresent invention, a frame 41 (FIGS. 1, 3, 6 and 8) is molded integrallywith U-tube 19. Frame 41 includes sides 42 and 43 and a bottom 44. Sides42 and 43 and bottom 44 terminate at U-shaped mirror-image edges 45 and45′ (FIGS. 1A, 6 and 8) which lie in the same planes as the outer edgesof ridges 27 and 27′, respectively. Thus, the permeable covers 40 and40′ are extended to provide covers 47 and 47′, respectively, which arebonded to the edges 45 and 45′, respectively, of frame 41 by the samemeans as covers 40 and 40′ are bonded to ridges 27 and 27′,respectively. Thus, covers 47 and 47′ serve as filters to filter the oilat the bottom of accumulator 11 which passes into the space within frame41 and thereafter enters oil-receiving hole 26. As noted above relativeto covers 40 and 40′, both covers 47 and 47′ need not be permeable, asonly one permeable cover 47 or 47′ may be adequate for filtration. Also,instead of using permeable fabric on frame 41, metal or plastic filtermesh or screening may be bonded to one or both sides of frame 41. Also,frame 41 need not be limited to the specific shape shown but may beshaped otherwise. While the bottom of frame 41 is shown spaced from thebottom of portion 12 of the accumulator housing 11, frame portion 44 mayrest on bottom 48 to stabilize the U-tube.

[0048] In FIGS. 9, 10 and 11 another embodiment of a U-tube 50 isdisclosed which can be a part of an integrated U-tube and adsorbentunit, such as described above relative to FIGS. 1-8. The U-tube 50 isfabricated by injection molding in two halves 51 and 52 (FIGS. 10 and11), and thereafter the two halves are bonded to each other by anysuitable means including but not limited to vibration welding, fusionwelding, ultrasonic welding or gluing. The material of U-tube 50 may bepolypropylene or any other suitable resin. Aside from the fact thatU-tube 50 is formed from two halves which are bonded to each other,U-tube 50 contains all of the specific structure described aboverelative to the U-tube 19 of FIGS. 6-8. It is used in the same mannerwith the placement of the adsorbent in a space 53 and the use of coverswhich are bonded to ridges 27 a and 27 b which are analogous to ridges27 and 27′, respectively, of FIGS. 6-8. It also includes a frame 41 awhich is identical to frame 41 of FIGS. 6-8 and which is utilized in thesame manner. Also, the two halves 51 and 52 provide a filter hole 26 awhich is analogous to filter hole 26 of FIGS. 6-8.

[0049] In FIGS. 15 and 16 a U-tube 19′ is shown which includes acompartment 60 for containing a refrigerant tracer dye 66 which is inthe form of a wafer but can be in granular form or in any other suitableform. Compartment 60 is outlined by a frame 61 which has outer edges 62and 62′ which lie in the same plane as the outer edges 45 and 45′ offrame 41 and the outer edges of ridge portions 31 and 31′ of ridges 27and 27′, respectively. Frame 61 includes substantially vertical portions64 and 65 which are connected by rounded upper portion 67. Since theedge 62 of frame 61 and edge 45 of frame 41 and the edge of ridge 27 alllie in the same plane, the covers 40 will be bonded to theaforementioned coplanar outer surfaces. An analogous relationship existswith cover 40′ relative to edges 62′, 45′ and the edge of ridge 27′.

[0050] It will be appreciated that while the U-tube of FIGS. 15 and 16shows both frames 41 and 61 along with the ridges 27 and 27′, it will beappreciated that each of the foregoing components can be incorporatedseparately with a U-tube. In this respect, it will be appreciated that aU-tube may have only ridges 27 and 27′ if the filtering and die tracerfunctions are not desired. Also, a U-tube may have only a frame, such as41, having opposite outer edges, such as 45 and 45′ if only a filteringfunction is desired. Also, a U-tube may have incorporated therein only aframe, such as 61, for containing a refrigerant tracer dye. In thisrespect, the tracer dye, whether it is in wafer or granular form, can beinserted into compartment 60 defined by frame 61 after one side of frame61 has been covered and before the opposite side of frame 61 has beencovered. The covers for frame 61 are preferably portions of covers 40and 40′, as discussed above. However, in an embodiment of a U-tubewherein a frame, such as 61 is used by itself, separate porous coverscan be bonded to one or both opposite sides of frame 61. While porouscovers, such as 40 and 40′, have not been shown in the embodiment ofFIGS. 15 and 16, it will be understood that such covers, as discussedrelative to FIGS. 1-4, are used in the embodiment of FIGS. 15 and 16.

[0051] In FIGS. 12-14 the method of fabricating the integrated U-tubeand adsorbent unit 10 is shown. The first step is to bond cover 40 toridge 27 by the application of suitable heat and pressure or byultrasonic welding or by gluing them together or by any other suitablemeans of attachment. The second step is shown in FIG. 13 wherein theadsorbent unit is dumped into the space between legs 20 and 22. Thethird step is to seal the cover 40′ to ridge 27′ by suitable heat andpressure or by ultrasonic welding or by any other suitable means tothereby confine the adsorbent 39 between the legs 20 and 22 and returnbend 21.

[0052] While the above description has been limited to a plastic U-tube,it will be appreciated that a metal U-tube can also be used if thecovers, such as 40 and 40′, are suitably bonded thereto, as by gluing orby any other suitable means.

[0053] While only one opening 26 at the lowermost underside of U-bend 21has been shown in the embodiment of FIGS. 1-7, it will be appreciatedthat a plurality of openings 46 can be provided as shown in FIG. 6A orin any other suitable manner.

[0054] In the above description, primed numerals represent mirror-imagecounterparts of unprimed numerals.

[0055] The above description has used the terminology U-tube. However,the U-tube 19 is sometimes referred to as a J-tube. It is to beunderstood the terminology U-tube is intended to mean any tubearrangement having spaced legs connected by a return bend such thatthere is a space between the legs.

[0056] In FIGS. 17-23 a modified form of integrated U-tube and adsorbentunit is shown. The adsorbent unit 70 includes a cover 71 consisting ofsides 72 and 73 fabricated of web-bonded porous polyester fabric whichhave been sealed to each other at fused edge 74 which consists ofstraight portions 75 and 77 and curved portions 79 and 80. The cover 71is filled with a suitable adsorbent 81, which is the same as adsorbent39 described above.

[0057] The adsorbent unit 70 is integrated onto U-tube 82 which isformed of blow-molded polyethylene plastic. U-tube 82 it has the shapeof the U-tube 19 described in detail above in FIGS. 1-8 except thatU-tube 82 is not shown with the filter frame 41. More specifically, theU-tube 82 includes straight pipes or legs 83 and 84 connected by U-bend85. It also has ears which may be identical to ears 18 described above.A ridge 87 is molded integrally with straight pipes 83 and 84 and U-bend85. Ridge 87 includes straight portions 89 and 90 connected by curvedportions 91 and 92.

[0058] The integrated U-tube and adsorbent unit 94 is shown in FIGS.21-23. The fused edge 74 of adsorbent cover 70 is fused to ridge 87 byany suitable fusing method as described above wherein the plastic fusededge 74 of adsorbent container 70 is bonded by fusion to ridge 87 of theU-tube 82. The bonding by fusion can be by any of the methods notedabove, namely, by heat fusion, ultrasonic welding, vibration welding orany other type of fusion or the use of bonding cement or any othersuitable means of attachment. In the fully integrated position,adsorbent unit 70 occupies the position shown in FIGS. 21-23 wherein theside 73 of the cover 71 is substantially aligned with the outer edges oftubes 83 and 84, and the body of the adsorbent unit is located withinthe legs 83 and 84 and return bend 85 of the U-tube 82, as shown inFIGS. 22 and 23. The side 73 of cover 71 will generally occupy thepositions shown in FIGS. 21-23. If there is a requirement for moreadsorbent than can be fitted into the confines of cover sides 72 and 73,sides 72 or 73 can be extended so as to project outwardly beyond theperiphery of the U-tube. In this respect, side 73 could projectoutwardly to the right in FIG. 23 and side 72 can project outwardly tothe left beyond its position shown in FIG. 23.

[0059] While the U-tube 82 has been shown with a ridge 87 thereon, itwill be appreciated that the edge 74 of an adsorbent cover could befused directly to the U-tube if it does not have a ridge 87. It will beappreciated that the cover 71 can be extended beyond that shown, ifdesired, for bonding to the U-tube.

[0060] The construction of the adsorbent unit 70 and the U-tube 82, asshown in FIGS. 17 and 23, precludes the incorporation therein of aseparate frame for a filter and for a refrigerant tracer, as describedabove. However, there is no reason that each of the foregoing framescannot be incorporated into the U-tube 82, if desired. In this respect,the incorporation of a filter frame need not require a change in theconfiguration of the adsorbent unit 70. However, if a refrigerant tracerframe is incorporated in the manner shown in FIGS. 15 and 16, then theconfiguration of the adsorbent container would have to be modifiedaccordingly. Alternatively, the refrigerant tracer compartment could beformed so that it extends outwardly from the side of one of the tubes 83or 84 or the U-bend 85 and the tracer can be contained in such a frameby separate porous covers.

[0061] While preferred embodiments of the present invention have beendisclosed, it will be appreciated that it is not limited thereto but maybe otherwise embodied within the scope of the following claims.

1. An integrated U-tube and adsorbent unit comprising a U-tube havingfirst and second legs and a return bend, a space between said first andsecond legs, adsorbent in said space, and at least one permeable coverbonded to said legs.
 2. An integrated U-tube and adsorbent unitcomprising a U-tube having first and second legs and a return bend, aspace between said first and second legs, adsorbent in said space, firstand second opposite sides on said first and second legs, respectively,and a permeable cover bonded to at least one of said first and secondopposite sides.
 3. An integrated U-tube and adsorbent unit as set forthin claim 2 including an oil-pickup opening in said return bend, a frameextending downwardly from said return bend, a second space defined bysaid frame and in communication with said oil-pickup opening, and asecond permeable cover secured to said frame.
 4. An integrated U-tubeand adsorbent unit as set forth in claim 3 wherein said second permeablecover comprises an extension of said permeable cover.
 5. An integratedU-tube and adsorbent unit as set forth in claim 2 including a secondpermeable cover bonded to the other of said first and second oppositesides.
 6. An integrated U-tube and adsorbent unit as set forth in claim5 including an oil-pickup opening in said return bend, a frame extendingfrom said return bend, a second space defined by said frame and incommunication with said oil-pickup opening, and a third permeable coversecured to said frame.
 7. An integrated U-tube and adsorbent unit as setforth in claim 6 including a fourth permeable cover bonded to saidframe.
 8. An integrated U-tube and adsorbent unit as set forth in claim7 wherein said frame has third and fourth opposite sides, and whereinsaid third and fourth permeable covers are secured to said third andfourth opposite sides, respectively, of said frame.
 9. An integratedU-tube and adsorbent unit as set forth in claim 8 wherein said third andfourth permeable covers are extensions of said first and secondpermeable covers, respectively.
 10. An integrated U-tube and adsorbentunit as set forth in claim 2 wherein said permeable cover is bonded tosaid first and second legs and said return bend on one of said first andsecond opposite sides.
 11. An integrated U-tube and adsorbent unit asset forth in claim 10 including a second permeable cover bonded to saidfirst and second legs and said return bend on the other of said firstand second opposite sides.
 12. An integrated U-tube and adsorbent unitas set forth in claim 10 including a ridge on said first and second legsand said return bend on said one of said first and second oppositesides, and wherein said permeable cover is bonded to said ridge.
 13. Anintegrated U-tube and adsorbent unit as set forth in claim 12 includinga second ridge on said first and second legs and said return bend on theother of said first and second opposite sides, and a second permeablecover bonded to said second ridge.
 14. An integrated U-tube andadsorbent unit as set forth in claim 2 including a ridge on one of saidfirst and second opposite sides, and wherein said permeable cover isbonded to said ridge.
 15. An integrated U-tube and adsorbent unit as setforth in claim 2 including first and second ridges on each of said firstand second opposite sides, respectively, and wherein said permeablecover is bonded to said first ridge, and a second cover bonded to saidsecond ridge.
 16. An integrated U-tube and adsorbent unit as set forthin claim 2 wherein said first and second opposite sides include saidreturn bend, and a ridge on one of said opposite sides of said first andsecond legs and said return bend, and wherein said permeable cover isbonded to said ridge.
 17. An integrated U-tube and adsorbent unit as setforth in claim 2 wherein said first and second opposite sides includesaid return bend, first and second ridges on said first and secondopposite sides, respectively, and wherein said permeable cover is bondedto said first ridge, and a second cover on said second ridge.
 18. Anintegrated U-tube and adsorbent unit as set forth in claim 17 whereinsaid second cover is permeable.
 19. An integrated U-tube and adsorbentunit as set forth in claim 2 including a partition in said space betweensaid legs.
 20. A method of fabricating an integrated U-tube andadsorbent unit comprising the steps of providing a U-tube having legsand a return bend with a space between said legs and first and secondopposite sides on said legs, providing a first cover on said first sidesof said legs, placing adsorbent between said legs, and bonding a secondcover to said second sides of said legs.
 21. A method of fabricating anintegrated U-tube and adsorbent unit as set forth in claim 20 whereinsaid first cover is bonded to said first side.
 22. A method offabricating an integrated U-tube and adsorbent unit as set forth inclaim 20 wherein at least one of said first and second covers ispermeable.
 23. A method of fabricating an integrated U-tube andadsorbent unit as set forth in claim 20 wherein said first and secondcovers are permeable.
 24. A U-tube comprising spaced legs and a returnbend, an oil pick-up hole in said return bend, a frame formed integrallywith said return bend to define a space in communication with said hole,and filter material bonded to said frame on the opposite side of saidspace from said hole.
 25. A U-tube as set forth in claim 24 wherein saidframe has first and second opposite sides, and filter material bonded toboth said first and second opposite sides.
 26. A U-tube comprisingspaced legs and a return bend, and a refrigerant tracer dye compartmenton one of said legs and return bend.
 27. A U-tube as set forth in claim26 wherein said refrigerant tracer dye compartment is on said returnbend.
 28. A U-tube as set forth in claim 26 wherein said refrigeranttracer dye compartment is molded integrally with said one of said legsand said return bend.
 29. A refrigerant tracer dye constructioncomprising a tube, and a refrigerant tracer dye compartment on saidtube.
 30. A refrigerant tracer dye construction as set forth in claim 29wherein said refrigerant tracer dye compartment is molded integrallywith said tube.
 31. An integrated U-tube and adsorbent unit comprising aplastic U-tube having first and second legs and a return bend, and aself-contained adsorbent unit consisting of a plastic cover withadsorbent therein with said cover being fused to said plastic U-tube.32. An integrated U-tube and adsorbent unit as set forth in claim 31including an edge on said cover, and wherein said edge is fused to saidU-tube.
 33. An integrated U-tube and adsorbent unit as set forth inclaim 32 wherein at least a portion of said adsorbent unit is positionedbetween said legs.
 34. An integrated U-tube and adsorbent unit as setforth in claim 31 including a second cover bonded to said first cover.35. An integrated U-tube and adsorbent unit comprising a plastic U-tubehaving first and second legs and a return bend, adsorbent between saidlegs, a plastic cover confining said adsorbent between said legs, andsaid plastic cover including a portion which is fused to at least one ofsaid legs.
 36. An integrated U-tube and adsorbent unit as set forth inclaim 35 wherein said cover completely encircles said adsorbent.
 37. Anintegrated U-tube and adsorbent unit as set forth in claim 35 whereinsaid adsorbent is in direct contact with both said legs and said cover.38. An integrated U-tube and adsorbent unit comprising a plastic U-tubehaving first and second plastic legs and a plastic return bend, aplastic cover, adsorbent confined by said plastic cover, and saidplastic cover being fused to said plastic U-tube.
 39. An integratedU-tube and adsorbent unit as set forth in claim 38 wherein said plasticcover completely encircles said adsorbent.